Right now, most news releases tell you that they keep the $500, and the person files 2020 getting their own $1,200. But this is what the IRS shows:

"The IRS will provide information on what actions you need to take when you file your 2020 tax return when they are available."

What you need to do is Sign Up for IRS e-newsletters, to get the updates to your own inbox.

https://service.govdelivery.com/accounts/USIRS/subscriber/new